Potato plants of cultivars Agata and Caesar attacked by root-knot nematode (Meloidogyne sp.) showing root systems with multiple galls and protuberances in tubers were detected in Contenda, municipality traditionally producer of the Paraná state. Adult females of Meloidogyne sp. extracted from the potato roots and tubers and submitted to electrophoresis showed esterastic band profile as Meloidogyne ethiopica (Est E3). Using a pure population of M. ethiopica, potato plants of different cultivars, kept in pots with sterilized soil in greenhouse, were inoculated with 5,000 eggs + second stage juvenile of the nematode. Fifty-five days after the inoculation, each plant was evaluated by counting the number of galls and eggs, and determined the nematode reproduction factor (RF) in the different tested genotypes. The cultivar Eliza behaved as moderately resistant to M. ethiopica; ‘Ana’, ‘Bel’, ‘Agata’, and ‘Catucha’, as moderately susceptible; ‘Clara’, ‘Asterix’, ‘Cris’, and ‘Cota’, susceptible; and ‘Caesar’, as highly susceptible.